Detergent and application thereof



Feb. 26, 1935. L. H. ENGLUND 1,992,692 DETERGENT AND APPLICATION THEREOF Filed April 20, 1952 fivezzz or' humans. 26, 1935 DETERGENT AND APPLICATION THEREOF Leonard H. Englund, Winnetka, 111., assignor of two-thirds to Benjamin Baslaw and one-third to Charles N. Ash, Chicago, Ill.

, Application April 20, 1932, Serial No. 606,476

5 Claims.

The present invention relates to improvements in detergents and the application thereof, more particularly in washing operations such; as the washing of dishes, and will be fully understood 6 from the following specification, illustrated by the accompanying drawing, in which Figure 1 is a diagrammatic sectional view through a washing device illustrating a method of use of the detergent in accordance with the present invention; and

Figs: 2 and 3 are detailedjsectional views, Fig. 3 on the section line 3, and Fig. 2 illustrating a modified method of use of the detergent .of the present invention.

The detergent and method of using the same in accordance with the present invention are more particularly applicablein washing operations in which a washing liquid is continuously recirculated from a suitable reservoir through the portion of the apparatus or device in which washing takes place and back to the reservoir, there being a constant overflow and a constant replenishment of the liquid in said reservoir. In accordance with this invention, I prepare and utilize a detergent in such manner as to permit a controlled-9rate of solution thereof, which may be adjusted in the manufacture of the detergent or by its arrangement in the device in which it is used to maintain a desired proportion of the detergent in the washing liquid. Although particularly applicable to such recirculating systems,

- it will be apparent that the invention is applicable in any situation which the detergent in the washing liquid is constantly wasted and requires replenishment. Hitherto, the replenishment of the detergent in washing liquids has been effected by the manual supply of powdered detergent material or of detergent supplied in some readily soluble form, with substantially immediate complete solution thereof, and such supply of detergent is ordinarily highly wasteful and ineflicient, since it is dependent upon the more or less competent judgment of the operator of the washing device, ordinarily unskilled, as to the requirements of the device.

In accordance with the present invention, I prepare the detergent in the form of a compact body or block of the detergent material, this block being so prepared and formed as to have a retarded solution rate. Such a retarded solution rate may be imparted to the detergent block bothin the physical operation of making the block and by incorporating into the block constituents having a-solution retarding effect.

As the principal constituent of the detergent block, I employ trisodium phosphate, preferably with a part or all of its normal water of crystal-' lization; I may also employ, with the trisodium phosphate. a small proportion of an additional detergent, such assoap, preferably to an extent not exceeding, 5% of the trisodium phosphate. When preparing the detergent block, the tri-' sodium phosphate, either alone or together with such added constituents as are employed, is compacted in a suitable press or briquetting machine under high pressure, say in excess of 10,000 lbs. per square inch. 1 preferably employ a pressure sufficiently high to cause an amalgamation or consolidation of the particles of trisodium phosphate similar to that characteristic of metamorphosed rock, pressures of the order of 50,000 lbs. per square inch and higher being suitable for this surpose. In ordinary practice I employ a pressure in the order of 80,000 lbs. per square inch in the manufacture of the blocks. Under 20 such pressures as have been hereinbefore set forth, the rate of solution of the detergent material is markedly reduced, solution taking place by an erosion process at the exposed surfaces of I the block. 25

To further control the rate of solution of the material of the block, I may incorporate therein solution retarding agents, acting either by water repelling action or by reduction of rate of solution. For example, to impart to the mass a par-- 30 tially water repellant action, I may incorporate as a constituent thereof a small proportion of a mineral oil, for example, a light mineral oil such as kerosene, or a water-insoluble soap, such as aluminum, zinc or other metallic stearate, oleate, palmitate, soap, or the like, or both. The proportion of such water repellant material is relatively small, say up to 5% and in general, from 1 to 2%. Thus, I may incorporate in thecom position of the block, from 1 to 3% of kerosene or aluminum stearate, or preferably of kerosene con-I taining in solution from 5 to 10% of the desired water-insoluble soap, such as aluminum stearate.

As hereinbefore set forth, a slow dissolving constituent may be incorporated into the composition of the detergent block, either with or with-' out the water repellant material. For this purpose, I have found a solution of an alkaline metal silicate of high silica content suitable; preferably a solution of a soluble silicate of an alkali'metal, such as sodium, containing 50% or more {of silicate. The proportion .of sodium silicate so incorporated should not exceed 20% of the total composition and ingeneral should be in the order 0f3 to 10%. v a u As an example of a detergent ,block prepared in accordance with the invention, I may employ a mixture containing trisodium phosphate, a. small proportion of soap, and sodium silicate solution and compress it into a block at a suitable pressure to form a coherent mass. Forexample, such a composition may contain 90 parts trisodium phosphate, 5 parts sodium silicate solution containing about 65% silicate of high silica content and 5% of a vegetable oil soap of about 50% soap content. This mixture is compacted as hereinbefore set forth, forming a slowly soluble detergent block.

I prefer, hpwever, to incorporate water repel-.

lant agents into the block, as hereinbefore set forth. My preferred composition contains 90% trisodium phosphate, 5% sodium silicate solution, 2 of a vegetable oil soap of about 50% soap content and 2 of a kerosene solution containing about 5% of its weight of aluminum stearate. Small proportions of mild perfumes or other constituents may be' employed to mask the odor of the kerosene if a highly refined, odorless kerosene is not employed. The kerosene or light mineral oil is of value also in improving the detergent action of the composition as a lubricant for the dies of the press in which the blocks are made.

In such a composition, the proportion of the water repellant agents may be increased and the sodium silicate solution eliminated entirely, and kerosene alone may be employed as the water repellant agent, or a suitable proportion, say up to 5% of the water insoluble soap employed as the water repellant agent. v

The composition is thoroughly mixed and may then be compressed under suitable pressure to form a coherent'mass and preferably under a high pressure beyond its yield point, in excess of 30,000 to 40,000 lbs. per square inch, to cause a change in structure with unification or metamorphosis of the entire mass, yielding a poreless block resembling in appearance a metamorphosed rock. In forming the mixture, I prefer to heat the constituents together to the fusion point, which is relatively low by reason of the low temperature of fusion of the crystalline trisodium phosphate, cool and granulate the fused mass, and then subject the material to pressure to form the detergent block, as hereinbefore set forth.

In Fig. 1 of the drawing, I have illustrated the use of the block of the present invention, in connection with a typical dish-washing machine, diagrammatically illustrated. In the drawing, the numeral 5 indicates the casing of the machine, provided at its entering end with an opening 6, and at its exit end with an opening '7, shielded by canvas curtains 8. The dish-containing trays 9 are pushed through the machine,

- resting on tracks 10. Centrally of the bottom of the machine there is provided a reservoir 11,.

which may be divided into two sections by a partition 12. On each side of the reservoir, the bottom of the casing slopes downwardly to the reservoir, as indicated at 13. In each section of the. reservoir 11, there is provided a pump 13, by which the water therefromis forced through the pipes 14 and 15 respectively (shown in dotted .--lines), which are outside of the casing, to sets of jsprays designated respectively 16 and 17. Each set of sprays comprises one above the track carrying the dishes and one below the track. In addit'ion, near the exit end of the casing, sets of sprays 18. above and below the dish-supporting each section of the reservoir 11. Valved overflow pipes 21 are likewise provided in each section of the reservoir 11.

In the operation of the machine, the dishsupporting trays are pushed in through the opening 6, thereby forcing the preceding trays through the machine and out through the opening 7 The pumps 13 are set in operation from the power shaft 22, thereby circulating the water from the sections of the reservoir through the sets of sprays 16 and 17, by which sprays of the washing liquid are delivered against the dishes being passed through the machine. As they near the exit end of themachine, sprays of fresh hot water are delivered against the dishes from the sets of spray-pipes 18. The water discharged in the machine drains to the reservoir 11, and the fresh hot water supplied through the spray pipes 18 constitutes a source of fresh clean water for replenishing the washing liquid, this supply being compensated for by the withdrawal of washing liquid through the overflows 21.

In prior operation of such machines, the detergent properties of the washing liquid have been maintained by the addition of powdered or flaked detergent material to the reservoir from time to time, as the operator believed it necessary. In accordance with the present invention, by means of the detergent blocks hereinbefore described, a constant replenishment substantially in accordance with the rate of use of the machine is provided for by placing the block at a suitable point in the path of circulation of the washing liquids.

As indicated in Fig. 1, this may be accom-- plished by placing a detergent block of the character herein described, and indicated by the nuit receives a partial spray from one of the spraying devices, for example, the upper spray of the set 16, but preferably where it does not receive the full force of the spray. The block thus interposed in the circulation of the washing liquid slowly dissolves sufiiciently to maintain the detergent composition of the washing liquid in the reservoir 11, during operation. In such use, a 3 lb. block of the detergent has been found to compensate for the replenishment of the washing liquid to the extentof 300 gallons of fresh hot water.

In beginning the operation of the washing machine, in order to bring up the washing liquid to the desired detergent composition, the reservoir 11 may be filled with fresh hot water, and the latter recirculated without overflow or replenishment until suiiicient of the detergent has been dissolved from the block. In order to bring up the composition of the detergent liquid more quickly, however, in starting operation a detergent block may be temporarily placed on one of the skimming screens 20, where it receives more directly the force of the sprays and when the desired composition of liquid is secured, the block may be removedfrom the skimming screen and placed upon the screen support 24, where, in continuing operation, only sufficient, detergent is dissolved from the block to maintain the composition of the detergent liquid.-

In Figs. 2 and 3, I have illustrated a modified form of operation in accordance with the present invention. The detergent block is here formed as a cylinder 25 with a central bore or opening 26, and is placed in an enlarged cylindrical casing 27 provided on one of the water circulating -meral 23, on asc'reen support 24 provided near the entering end of the machine at a point where pipes, for example, the pipe '14. .I'he casing 27 may suitably be provided with a hinged door 28 for insertion of the block. In this mode of operation, the circulating washing liquid is forced through the bore of the cylindrical block, which is gradually dissolved, its rate of solution being controlled by the incorporation of solution controlling agents as hereinbefore described to secure the desired slow rate of solution of the detergent.

Where further control of the rate of solution of the block is desired, as in the type of operation illustrated in Figs. 2 and 3, a block of the character hereinbefore described and containing sodium silicate may be immersed in a solution capable of reacting with the silicate present in the block to form an insoluble silicate. For example, th e block may be immersed in a solution of calcium chloride, magnesium sulfate or barium chloride, preferably the former. If a more impervious coating over the outer surface of the block is desired, it may be subsequently immersed again in a silicate solution, which reacts with the calcium or other alkali metal salt remaining on the surface of the block to form a further insoluble silicate coating.

Although the present invention has been described in connection with specific details of the production and utilization of the detergent block in accordance with this invention, it is not intended that these details shall be regarded as I limitations upon'the scope of the invention except in so far as included in the accompanying drawing.

This application is inpart a continuation of my prior application Serial No. 412,917, filed December 9, 1929.

I claim:

1. A dense coherent detergent block comprising trisodium phosphate with at least part of its water of crystallization, aluminum stearate, a light mineral oil, and a binder consisting originally of a sodium silicate solution, the trisodium phosphate constituting of the block, and

the said block being compacted to a state of metamorphosis of the trisodium phosphate.

2. A block as set forth in claim 1 containing a small proportion of a water-soluble soap.

3. A block as set forth in claim 1 in which the mineral oil is kerosene.

4. A dense coherent detergent block comprising approximately 90% trisodium phosphate, 5% of sodium silicate solution, 2 /g% of-a vegetable oil soap and 2%% of a kerosene'solution containing about 5% by weight of aluminum stearate, the said block being compacted to a state of metamorphosis of the trisodium phosphate.

5. A block as set forth in claim 1 which has been compacted under pressures of the order of 30,000 pounds per square inch.

LEONARD H. ENGLUND. 

